Recently Urban Flooding is a big issue. So writing some important points, which can be elaborated further keeping in exam point of view;

Reasons:

# Wetland encroachment for development purpose. For example Chennai and Bangalore. Bangalore was once called as city of lakes, now all are lost. Wetlands are not only Biodiverse region bit also acts as buffer in times of Heavy rainfall.

# Stopping the natural flow of drains. For example Mithi river has been destroyed due to dumping of wastes in Mumbai. Jhelum river has been encroached in Srinagar, as we saw a major flooding there. Construction work has created a lot of problems in natural flow of these rivers. So in times of Heavy rainfall of more water they get flooded.
# Concrete roads reduce percolation, as a result water flows here the and there. Happen in cities, can be given example of Delhi and Gurgaon.
# Climate Change.; New reports are coming that frequent spells will increase due to climate change. They will also increase flow in rivers due to melting of glaciers. Can quote IPCC report. Example is Houston in Texas, US. The cyclone created havoc there. Also Wetland encroachment increased the problem in Houston.

Solution:
# River Flood Zoning. Here land use planning is done according to the potential of a river for flooding. Prohibited zone and Regulated zone are demarcated.

# Wetland preservation can solve many problems of urban flooding.
# Urban Greening. Increasing more parks etc for percolation and proper drainage.
# Building storm drainages; which will be used in times of storms or heavy water flow.
Proper care should be given to Disaster management aspect. Such points can also be made on general Flooding.